Bit grab



C- O. STEED March 12, 19 63 BIT GRAB Filed May 9, 1960 m m p f 2 2 E- 4m M h! v a ll 3 a w m H MW w m w. m. a H 6r w c HA PL 5 9: s TEED IN VEN TOR threaded connection (pin) itself has broken off.

United States Patent() 3,081,123 BIT GRAB Charles 0. Steed, 47 AndrewsHighway, Odessa, Tex.

0 Filed May 9, 1960, Ser. No. 27,889

3 Claims. (Cl. 294-8629) This invention pertains to fishing tools andmore particularly to a tool specially designed to grapple drill bitsfrom within oil wells.

A problem exists in the drilling of oil Wells with the occasional lossof a bit within the hole. This may be because the bit with the threadedconnection has totally come off as illustrated in FIG. 1 or it may bethat She ne of the means to fish these out of the prior practice is tolower an explosive charge down within the bit, detonate the chargethereby destroying the bit, then fishing the pieces out with magneticmeans.

An object of this invention is to provide a fishing tool speciallydesigned to remove drill bit-s from oil wells.

Another object of this invention is to provide a tool which has jets forwashing debris away from tools so that said tool may engage the biteasily.

Further objects are to achieve the above with a device that is sturdy,compact, durable, simple, and reliable, yet inexpensive and easy tomanufacture.

The specific nature of the invention as well as other objects, uses, andadvantages thereof will clearly appear from the following descriptionand from the accompanying. drawing, in which:

FIG. 1 is an elevational view of a tool according to this invention justabove such a bit it is designed to remove.

FIG. 2 is a top view of the tool.

FIG. 3 is an axial sectional view of the tool taken on line 3-3 of FIG.2.

FIG. 4 is a partial sectional view at a larger scale taken on line 44 ofFIG. 3.

As may be seen in the drawings, one of the principal features of a toolaccording to this invention is the cylindrical barrel which forms thebody thereof.

Attached to the outside of the barrel are three pairs of ribs 12. Theribs extend axially of the barrel on the outside thereof. They arearranged in pairs, so that a slot is formed by each pair. Bolt 14 aboutmidway of the ribs, extends across the slot between each pair of ribs.Each bolt is normal to the slot, therefore parallel to a tangent of thecylindrical barrel 10.

An arm 16 is within each of the slots. Bolt 14 extends through a holeinthe arm thus pivoting the arm to the ribs. The arm has a lower footportion 18 which extends below the body of the barrel. The shank end 20is above bolt 14. Two holes are in the barrel through the slot radiallyof the barrel. Cups 22 are attached by welding or otherwise to thebarrel and extending therein. A spring 24 is within each cup. Thesecompression springs push against the shank of the arm causing the arm 16to rotate about the bolt 14. This causes the shanks 20 collectively toextend outward and thefoot portions 18 collectively to contract.

On the extreme lower end of the foot of each arm there is a earn surface26. When the tool passes over a bit, the cam surfaces 26 will cause thelower portion of the arms to rotate about bolt 14, compressing thesprings 24, enlarging the opening between the claws 28. When the footportion passes over the largest diameter of the bit, the springs willcause claws 28 to rotate about bolt 14, toward the axis of the barrel.This will cause contraction of the opening between the claws 2'8 andwill firmly secure the tool to the bit. I have found most of these bitsare in the upright position.

3,081,123 Patented Mar. 12, 1963 The barrel 10 is attached to sub 30.The top of the sub is threaded, thus making it adapted to attach to thesame string of drill stem to which the bit was previously attached. Itis therefore possible to circulate fluid through the tool. Theattachment of the sub to the barrel is by threading or any otherconvenient means.

The bit may be imbedded in debris such as mud. In such instances it isdesirable to provide means for removing or loosening said debris. Onemethod is to weld or attach a plate 32 transverse the barrel therein.The plate has axial nozzle 34 therethrough. The nozzle is directeddownward so that fluid passing through drill stem (not shown) and subwill be directed in a jet With great force upon the bit, cleaning debrisaway from it.

Also tubes or other passageways 36 are provided from the barrel upstreamof the plate. The connection of the top of the tube in opening 42through the barrels upstream of the plate is by any conventional means.Upstream from the plate and nozzle there will be higher pressure ifthere is considerable fluid flow through the tool. The lower end 38 ofthe tubes will discharge upon the bit adjacent to the position of theclaws 28. The jet of fluid coming through the tool will clear awaydebris from this most critical area where the claws engage.

Pads 40 are attached to the extreme lower end of the barrel within theslots so that the foot ends of the arms do not hang against the side ofthe barrel itself but strike the pads 40.

It will be noted that the foot portions 18 of the arms below the barrelare tapered toward the axis. This is to prevent them from digging intothe sides of the open Well causing excessive material to cave into thewell. Also it will be noted that the ribs extend above the shank 20' ofthe arms.

When the tool with the bit is being removed from the well, it is notpossible for a projection to strike the shank of the arms causing it tomove inwardly and the foot outwardly thus releasing the bit.

It will be understood when I speak of the claw 18 I mean that the bottomof the arm is somewhat L-shaped, however the foot of this L. anglesupward. The bottom of this element that angles upward toward the axis isthe cam 26. This claw might also be described as a hook or elbow orsnag.

It will be apparent that the embodiment shown is only exemplary and thatvarious modifications can be made in construction, materials, andarrangement within the scope of the invention as defined in the appendedclaims.

I claim as my invention:

1. A grapple for fishing drill bits from oil wells comprising: anupright cylindrical barrel, three pair of ribs extending on the outsideof said barrel axially thereof, each of said pair of ribs having a slottherebetween, a bolt extending across from each rib to the rib oppositethe slot, an arm extending axially of said barrel in each slot, saidbolt extending through a hole in said. arm, a foot portion of said armextending below the limits of said barrel, a shank end of the armextending up, a spring for each arm, each spring biasing the shank endof the arm away from the barrel so that the foot portion is biasedinward, a cam on the extreme foot end of said arms, a claw above the camon each foot portion; so that as the grapple is lowered over a bit, thecams spread the arms and fit thereover, and when the grapple is raisedthe claw engages the bit to lift it with the grapple, and a means forcausing a jet of fluid to wash over the bit.

2. The invention as defined in claim 1, wherein said means for causing afiow of fluid to wash over the bit includes a plate extending transversethe barrel, said plate having a nozzle therein, said nozzle directedaxially along References fiterl in the file of this patent the bit. o

3. The invention as defined in claim 2 with the addi- UNITED STATESPATENTD tion of passages connecting to the barrel upstream of the886,868 Rohen et al. May 5, 1908 plate, said passages extending downalong the arms so 5 1,635,622 Henderson July 12, 1927 they direct astream of fluid along or about the hook 2,090,616 Erwin Aug. 24, 1937portion of each arm. 2,416,613 Costin Feb. 25, 1947 2,709,617 Lang May31, 1955

1. A GRAPPLE FOR FISHING DRILL BITS FROM OIL WELLS COMPRISING: ANUPRIGHT CYLINDRICAL BARREL, THREE PAIR OF RIBS EXTENDING ON THE OUTSIDEOF SAID BARREL AXIALLY THEREOF, EACH OF SAID PAIR OF RIBS HAVING A SLOTTHEREBETWEEN, A BOLT EXTENDING ACROSS FROM EACH RIB TO THE RIB OPPOSITETHE SLOT, AN ARM EXTENDING AXIALLY OF SAID BARREL IN EACH SLOT, SAIDBOLT EXTENDING THROUGH A HOLE IN SAID ARM, A FOOT PORTION OF SAID ARMEXTENDING BELOW THE LIMITS OF SAID BARREL, A SHANK END OF THE ARMEXTENDING UP, A SPRING FOR EACH ARM, EACH SPRING BIASING THE SHANK ENDOF THE ARM AWAY FROM THE BARREL SO THAT THE FOOT PORTION IS BIASEDINWARD, A CAM ON THE EXTREME FOOT END OF SAID ARMS, A CLAW ABOVE THE CAMON EACH FOOT PORTION; SO THAT AS THE GRAPPLE IS LOWERED OVER A BIT, THECAMS SPREAD THE ARMS AND FIT THEREOVER, AND WHEN THE GRAPPLE IS RAISEDTHE CLAW ENGAGES THE BIT TO LIFT IT WITH THE